efi_loader: Handle memory overflows

jetson-tk1 has 2 GB of RAM at 0x80000000, causing gd->ram_top to be zero.
Handle this by either avoiding ram_top or by using the same type as
ram_top to reverse the overflow effect.

Cc: Alexander Graf <agraf@suse.de>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Alexander Graf <agraf@suse.de>
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index df99585..71a3d19 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -220,7 +220,7 @@
 	switch (type) {
 	case 0:
 		/* Any page */
-		addr = efi_find_free_memory(len, gd->ram_top);
+		addr = efi_find_free_memory(len, gd->start_addr_sp);
 		if (!addr) {
 			r = EFI_NOT_FOUND;
 			break;
@@ -320,9 +320,9 @@
 
 int efi_memory_init(void)
 {
-	uint64_t runtime_start, runtime_end, runtime_pages;
-	uint64_t uboot_start, uboot_pages;
-	uint64_t uboot_stack_size = 16 * 1024 * 1024;
+	unsigned long runtime_start, runtime_end, runtime_pages;
+	unsigned long uboot_start, uboot_pages;
+	unsigned long uboot_stack_size = 16 * 1024 * 1024;
 	int i;
 
 	/* Add RAM */